By CHRISTOPHER WEBER and MICHAEL BALSAMO , Associated Press

LOS ANGELES (AP) — Police said they were trying to determine what prompted a man to shoot his grandmother and wound another woman before he crashed his car and ran into a busy supermarket, where he held dozens of people hostage in a tense standoff with scores of heavily armed officers outside.

A woman was shot and killed when the gunman ran into the Trader Joe’s supermarket in Los Angeles’ Silver Lake section on Saturday, but no hostages were seriously hurt before the man handcuffed himself and surrendered about three hours later, police said. The man’s grandmother was hospitalized in critical condition on Sunday.

The man shot his grandmother seven times and wounded another woman, who he forced into a car, police said. Officers tracked the car, gave chase and exchanged gunfire with the man, who crashed into a pole outside the supermarket and then ran inside, they said.

Frightened customers and workers dived for cover as police bullets fired at the man shattered the store’s glass doors.

Some people inside the supermarket climbed out windows, and others barricaded themselves in rooms as scores of police officers and firefighters and 18 ambulances converged on the scene and prepared for mass casualties.

Heavily armed officers in riot gear stood along the side of the store and used mirrors to look inside as hostage negotiators tried to coax the man into freeing his 40 to 50 hostages and surrendering.

At about 6:30 p.m., the man agreed to handcuff himself and walked out the front door, surrounded by four of the hostages. The unidentified man was immediately taken into custody.

Mayor Eric Garcetti congratulated police and firefighters for their work and mourned the loss of life at the Trader Joe’s, where he and his wife regularly shopped when they lived in the neighborhood.

“The heroism that was shown today was second to none, and the teams that were able to respond, secure the perimeter and engage in conversation with the suspect no doubt saved lives today,” he said.

Among those who survived the harrowing afternoon was 91-year-old Don Kohles, who lives in the neighborhood and was walking into the supermarket when he saw “two police cars coming like a bat out of hell” and the man crashed into the pole.

The driver got out, and police started firing at him as he ran toward the supermarket. Kohles hurried inside, and he and others took cover as the man ran in.

“Those bullets went right over the back of me as he was running right down the main aisle,” Kohles said.

Christian Dunlop, a real estate agent and actor who lives nearby and frequents the Trader Joe’s, was on a corner near the store when he saw four people run out. One person, an employee, was dragging an injured woman by the hands.

“She appeared lifeless,” Dunlop said.

He then saw about five employees hang out a second-floor window and drop to the ground and about 15 other people run to safety from the back of the store. Among them was a police officer carrying a small child, he said.

“I know all the employees,” Dunlop said. “I see them all the time. My heart was just racing and thinking about all the endless possibilities.”

Police Chief Michel Moore said the gunman made a “series of demands” during the standoff but crisis negotiators believed they could persuade him to surrender peacefully.

Police aren’t sure what led to the initial violence that produced the car chase and standoff. Moore said at about 1:30 p.m. the suspect shot his grandmother and another woman in a South Los Angeles home and then forced the other woman into his grandmother’s car. The other woman suffered a graze wound.

Officers tracked the car using a stolen-vehicle tracking system and tried to stop the man in Hollywood, but he refused to pull over, Moore said. During the chase, the man fired at officers, shooting out the back window of his car.

Outside the store, the man exchanged gunfire with police again and the woman was shot and killed, Moore said. It was unclear if she died from police gunfire or was killed by the gunman. Moore said police and firefighters responded quickly but could not save her.

Fire officials said six people, ranging in age from 12 to 81, were taken to the hospital. None had been shot, and all were in fair condition.